The randomized placebo-controlled clinical trial NCT02772887 has been designed as supplementation of l-citrulline in pregnant women with type 2 diabetes (Table 1), to evaluate whether l-citrulline could normalize plasma l-arginine/ADMA ratio, decrease maternal blood pressure and rise the levels of placental growth factor (PLGF), a marker of placenta functioning and angiogenesis. This evidence concerns the gene PGF and type 2 diabetes mellitus.